Hello sandroalvesbrasil,
From a brief search online 'service-datastore' appear to be repository locations for VxRail-related scripts/tools and as staging location for images - these are *likely* VMFS datastores used with excess on install device (as with any standard ESXi install) of insignificant size - step 1 should be to check if they are on the same controller as the vSAN devices, if so then you should not be considering using them for VM storage (logging/coredump/ISOs is generally okay if they are durable devices), step 2 should be to find out if they are of any usable size at all or just VMFs on excess space of install as I said above.
VMware Knowledge Base
Bob
